To a solution of 4-(((1S,2S)-1-hydroxy-2,3-dihydro-1H,1′H-[2,2′-biinden]-2-yl)methyl)benzoic acid (100 mg, 0.26 mmol), Et3N (157 mg, 1.56 mmol) and 2-amino ethanol (40 mg, 0.65 mmol) in DCM (5 mL), was added T3P (0.33 mL, 50 wt % solution in ethyl acetate, 0.52 mmol) and then stirred at room temperature for 12 h. The reaction mixture was quenched with water (25 mL) and extracted with DCM (3×25 mL). The organic layer was washed with brine (25 mL), dried over anhydrous Na2SO4 and evaporated under reduced pressure. The residue was purified by CombiFlash using 20% ethyl acetate in chloroform as an eluent to yield 76 mg (68%) of the title compound as an off white solid.
